


Growing Pains

by FionasEmbrace



Category: Big Hero 6 (2014)
Genre: Implied Hidashi, M/M, Uncomfortable details
Language: English
Status: In-Progress
Published: 2015-02-27
Updated: 2015-08-12
Packaged: 2018-03-15 11:15:23
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 5,096
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3445052
Author URL: https://archiveofourown.org/users/FionasEmbrace/pseuds/FionasEmbrace
Summary: <blockquote class="userstuff">
              <p>While the botfights were always a welcome distraction, Hiro is frustrated by the idea of growing up, and the pressures and difficulties that come along with it.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Heads up for some creepy descriptions of things... Reason mostly being, it refers to some pre-canon events. He is characterized a lot differently in this fic (less mature/less sure of himself) than any of my other works, for the sake of the story. I actually feel kind of bad about writing this and am not sure whether to pull it... So, if it's not already obvious- please consider this in a completely separate universe, a completely separate thing from any of my other fics.
> 
> No harm is intended by this literary work of fiction.
> 
> Edit: 3/21/2015 Decided not to pull the fic.... false alarm, sorry for any confusion. Possibly will add another chapter.

"Oh, young man, you are altogether too sweet."

Tadashi was on cafe duty today. It didn't happen terribly often. He didn't mind too much. Cass was normally able to handle the cafe duties by herself, but there were occasional spikes in traffic, so he helped out, waiting tables and running the register. 

"I bet you say that to _all_ the guys, Mrs. Inoue."

Wearing a neat green apron over his normal clothes, he smiled warmly at the elderly couple, standing next to their table. 

"Hiro, can you put these dishes away in the back? Please, and thank you." Cass wasn't about to let Hiro completely off the hook either. Not this, again. The boy rolled his eyes, took the stack of dishes from her, and trudged into the kitchen. There wasn't much he could say in the form of protest, except for begrudgingly doing what he was told and heading back to his room. 

Closing the door, the noise was faint downstairs. Fortunately for him it was a rather slow day today, and easy to tune out. 

Hiro lazed back in his bed. He didn't want to do the damn dishes anymore, and it was a mystery to him how exactly Tadashi put up with it. Doing all that on top of his normal chores, seemingly catering to Aunt Cass's every whim. He never chose to live someplace attached to a cafe, it made no sense he should have to do anything. 

Closing his eyes, he decided to think of something more uplifting. Like his next bot fight. So he won the last one, but admittedly he played the 'doe-eyed, unsuspecting newbie' card a little too hard, and the other guy probably went easy on him. There were lots of new upgrades he could make. Supercapacitors. Carbon-magnetic interfacing. When he gets the time, he should do a full software rewrite. There were times where the AI would get tripped up, totally preventable.

Mentally, he itemized all the parts he would need, and the order in which he would do it. A quick trip to the hobby store, then the hardware store, then he could take over the garage for the evening. Bang bang, done, shouldn't be too bad at all. He felt confident about all of that. 

But his mind wandered.

Puberty was a funny thing. It never really even occurred to him what was starting to happen until it was described to him in school. The stuff Baymax said, after Tadashi had brought him home, worked fantastically to embarrass him further. 

He got up, and did what had become a normal routine for him- he looked into the mirror and studied the ongoing changes to his body. He closely examined his chest for hairs. None yet, although Tadashi didn't have all that much on his chest either, since it didn't run in the family. Maybe, if he flexed his muscles enough, his arms could look a bit more martial and tough like his big brother's. Yeah, it was a stretch. They were still skinny as ever, and his legs too. The past year, he could feel he was quickly growing. Some days, he had this distracting soreness, growing pains in his knees and elbows. 

He looked in closely at this chin. Still nothing there. He wondered when he might have to start shaving his face. But the most important part was when he pulled the waistband of his pants out, and look down. His genitals had grown in size and started to look more developed, and there were some hairs down there. He had balls for a while now, but they looked more obvious than before. And that was around the same time he was capable of producing seed that- as it had been explained to him- he could put in someone. 

Being a genius and knowledgeable about all other manners of things. he'd been well educated on what it all meant for him. It was strange, and slightly terrifying, but he knew it was part of the slow, horrible process of developing into a man. Along with that, of course, was the constant, constant preoccupation with sex. 

It used to be an occasional curiosity. Something abstract and far-off, a mythological fable that existed only for adults. His cock sprang to life at the tiniest provocation, or nothing at all, or he would jizz while sleeping, or he would fantasize about it at the worst times, when he was trying to solve a problem or carry a reasonable conversation. He thought about it constantly, while at the same time it made him very nervous. 

And that one fateful day- he remembered it like it was yesterday. That day, when he was lying in bed, alone, like he was just now- but something was wrong. He felt... strange? Physically. He felt all the blood flush from his face. Maybe his bed was feeling a little too comfortable, and messing with his circulation, or something. No. He looked down.

There it was. Jutting really obviously out of the blankets... It was standing straight upright, and a lot bigger than usual. He stared down at it, wide-eyed. In truth, at fourteen he'd been getting erections for a while now, he knew what they were and roughly how the whole process worked. They just didn't 'do' much of anything for him, for the most part. If he ignored them, they went away. Or if he stroked it, it would sometimes feel kind of good, momentarily, but no fluid would come out. And, all would be well, and then it would be back to normal. 

But somehow, that felt different from the other times before it. He couldn't really place why. Maybe it looked bigger than normal, maybe his sensitivity down there was different, or the urge to do something about it was stronger. He felt his heart race. His breathing was a bit heavy. 

Tentatively- even though he knew he shouldn't, at a time like this- he reached down and touched it. When his finger left the head it sprang back, full of life, back into place. He had never seen it get that big and hard. And now, it was taking over his whole mind- it was all he could think about. Reaching down, he touched it again, this time petting it a bit, through the blankets. He let out a small gasp. 

What this was, he just needed more. He was about to sneak his hand under the blankets, and slip it inside his boxers, when-

"Hiro, which robot was it you lost, about a week ago?! I think I found it!" Tadashi asked loudly up the stairs. Damn perfect. And he was on his way up.

"I-I don't know!"

"I came across this, clearing out dishes. It was inside one of the cabinets downstairs. Yours, right?" He said, walking into the room, holding a small, long-deactivated botfighting robot. 

At the exact same time, Hiro flushed red in embarrassment and pulled himself into a fetal position on the bed. 

"What's wrong, Hiro? You don't look so good."

"I'm fine."

"Are you sure? Maybe you have a fever. Mrs. Tanaka's son's been sick too, something going around."

"I told you, it's fine!" He muttered 'why won't you just lay off', under his breath.

"Hey, you don't gotta act smart with me. I was just being nice. Anyway, I think this is yours." He handed Hiro the bot. It was indeed, his. Mochi must have got at it, and relocated it somewhere. 

Hiro took the bot in his hands, but at the same time, his position shifted such that he couldn't hide the _condition_ from Tadashi. Yes, it jutted out of the blankets like the most obvious thing in the world.

And of course, it caught Tadashi's eyes, since he wasn't blind. It took a second for it to register- the most painful second, ever. But the moment it did, Tadashi looked sheepish, and out of polite concern for his brother, immediately averted his eyes. It was easy to see the outline of Hiro's cock, sticking up like that. Actually, it was hard to miss. "O-oh, sorry." In a gesture that was half-playful, half-genuine, he covered his eyes with his hands. 

Hiro was mortified, embarrassed. He flushed bright red. "Tadashi!" He wanted to tell his brother to leave him alone to spare him some of this humiliation, but he couldn't even articulate the words.

"Sorry. I won't bother you." The older Hamada said. Hiro swore he peeked through his fingers.

Tadashi didn't want to make things worse than they already were. His hands still over his eyes, only removing them after he turned around, he left back downstairs to leave him alone. Great. Hiro laid back on his pillow, and stared at the ceiling. Well, if that wasn't the single most mortifying thing ever. 

Yeah, that was pretty bad. But still, not enough to make his situation go away.

Picking up where he left off, he reached down to touch it. It felt so good, he just needed more. He pulled off the blankets and pulled his boxers down so he could get a better look. Definitely looked bigger than usual. He knew he was growing each and every day... That included every last part of him. 

Actually, he was well aware that most other boys had had these types of experiences earlier than his age, and that he was somewhat of a late bloomer. His body was still so scrawny and likely had some growing left to do, too. Tadashi was always taller than him, even back when he was Hiro's age. What can you do. He was impressed by how it was starting to look now, and how much more it was looking like the stuff he had seen in those Internet videos which he had no business looking at. 

It was impossible to resist. He stroked it once, from the top down to the bottom, just to see how it felt. He felt his hips involuntarily thrust upward a bit, once the sensation hit. It felt amazing, unlike any gratification he got before, from doing this. The skin that normally covered the head was all pulled back, and it looked strange and a bit obscene. It felt so much more sensitive than normal. He stroked it again, then again, and again. He stifled back a gasp, from how unexpectedly good it was. Maybe this was really what sex felt like. No wonder all the adults were obsessed with it. Damn, why hadn't he tried this sooner? 

As great as it was, it felt a little bit dry. Then, he got the idea to spit into his hand to make things a bit easier. This, too, of course, came from those Internet videos. And yes, it felt like paradise. The stimulation was almost too much. It was almost frightening, how powerful and wonderful this feeling was. He had to do it, faster and faster, before he knew it he was vice gripping his member and tight as possible. Maybe, he should stop, if he wanted this to last longer. He just couldn't. 

Suddenly, he felt his body seize up. Seconds, which seemed like ages, of pure bliss took over, a surge rushing through his whole body culminating at his dick. And that's when it came out. His own semen, a huge amount of it- one spurt after another. He watched it, wide-eyed. This had never happened before. Even though he knew what it was. That was it- his seed, wasn't it? No one told him it would be this messy and hard to control. He tried to make sure it all went into his hands and not on the sheets or anywhere else. But there was so, so much of it. 

He collapsed backward, exhausted. Tadashi never came back up the stairs, although it would have been safe. The next time Hiro saw him, he acted perfectly natural. Of course. 

That's what happened- the first time. And the rest was history.

Ever since then, he couldn't take his mind off of sex. Sometimes, jerking off didn't feel like enough.

But what if he actually did meet someone? Would he be able to go through with it? He was nervous just having someone open his legs and look at it. Maybe his cock hadn't quite yet grown big enough, or the hairs looked too sparse in some places, or who knows what else. He figured he still had some growing to do yet. And the weirdest thing, was he felt receptive to sexual pleasure in other places, too. Sometimes, when he jacked off, he would play with his nipples, pinch them or play with them to the point of pain, or stick a finger in down there, or when his finger wasn't enough, he used whatever object he could find. He couldn't pinpoint exactly when it started feeling good, but somehow it did. He could do it until it was sore and it physically hurt. And somehow he had the stamina to jack off multiple times in a row. 

He didn't really want to always be this way. He didn't want to be constantly imagining getting fucked, getting head, or worrying about the future. 

To make things even more complicated, when he thought about getting fucked- it was never something that altogether seemed 'nice'. You know, where two people love each other and have sex on their wedding night and live happily ever after. He thought about men, grown men, taking him in different positions. Face down, or on his back. Or the one most common, lately, was more specific- pressed up against some wall, literally, in some dirty alleyway. 

Yeah, like that would ever happen, but so what. The image of it was so vivid, each time. He could feel their big cocks sliding right into him and- of course- they would love how tight he was. He loved how each of their perfect, muscular bodies felt against his. The men in the dream loved how his body was so small yet so ready for them. Each time, they would take their turns, fuck him with abandon, unprotected, all the way to completion and even finish inside of him. They would show him a good time, maybe even give him a reacharound, or he could do it himself, or another one of them would suck him off, it didn't matter. 

At the start, it was always a different stranger. Someone about a foot taller than him, maybe, with a nice body and a really charismatic something about him. And then, over time, it became just one person. No one else around. That man, in an alleyway, with no particular reason to be there. It didn't have to necessarily make sense. And at the same time, there was something- something awfully _familiar_ about him. That person, that all these visions converged on. Even though what was happening was undoubtedly so unbelievably dirty, there was something inexplicably reassuring about him, so that he didn't have to think twice about feeling safe and looked after.

Maybe these visions were all part of it. In general he didn't want to constantly be thinking about this, or the other new changes to his body, or worrying about how his junk looked. He didn't even know if he wanted someone looking at it. Fuck, he was hard again. He didn't know how many more years of this he would have to endure. He couldn't understand how Tadashi did it. 

Sometimes, while he would never tell anyone this, he wanted to return to a life of innocence. To go back and live in that nice, fanciful world of only robots and dinosaurs and fun things. Of course, like every child he had worries and troubles, things that made him sad, but he never had this all-consuming sense of fear. The longing for things he would never have. His friends at school, far older and going on with their own lives, who just didn't understand. 

All part of the frustration of existing in a world so horrible as this one. He just hated everything sometimes. He was self-conscious about his body now and he wished he didn't have to be weighed down with thinking about it all the time. He wished that he could just stop time, and stop the humiliating physical processes he was going through. The unwanted erections were the worst. He felt like everyone was looking at him and looking 'down there', checking just in case. He wished there was some ideal way of hiding it. He was nearly too embarrassed to talk about it with Tadashi, even. Everything used to be simpler, more carefree, more innocent. 

Sometimes he wished he could return to that time. Now, there was just the thing between his legs, swelling and aching with need, jutting out of his thin hips and scrawny body and demanding all his attention. He was too strong to cry. He didn't want to always be a slave to these desires. 

But underneath it all, there was still this feeling of uncontrollable longing, thinking back to that man from his visions. The more he thought about it, iterating over it again and again in his mind- he knew who that man was. As much as these thoughts should be forbidden to him, it gave him butterflies in his stomach, and gave the whole world a sense of perfection and fulfillment like nothing else did. It was the only thing that had any truth in it, or made any sense. If this was what growing up was, he could welcome it with open arms. 

As these visions occurred to him, he dumped his whole heart and soul into them- it was something different than his love for robots or computers- something more powerful and pure. If it got him into trouble, he could deal with the consequences later. Even if it was wrong, he accepted it. Maybe, someday, just maybe, he could tell Tadashi about all of this. About what he was experiencing, about these visions, and about that unnamed person.


	2. Chapter 2

**Summary for the Chapter:**

> It's been a crazy long time, but here it is- an update to this fic! Better late than never.

"We're outta milk."

"I know." Tadashi sighed. "I was gonna have my cereal with water. Decided against it."

"Oh god, that's gross." Hiro closed the fridge, glanced around the kitchen for a lead. Nothing immediately good. Then he opened it again, and settled on a big orange from the crisper. He took a paper towel, and had a seat diagonal from Tadashi and started peeling it. Tadashi took another spoonful of his oatmeal, and turned the page on his study guide.

"You read that comic I sent you?" Hiro grinned.

"Nope." He vividly recalled that e-mail forward from one of Hiro's online friends. Took one look at the cover, and decided it would be a 'no.' "Why would I wanna read about people getting murdered like that?"

"It's _so_ messed up."

"I know. Which is why I'm better without that in my life. Come on."

"Lemme know what you think."

He sighed. Tadashi was not a morning person. "Will do." They never really had the same taste in comics, anyway. Hiro liked particularly gruesome stuff, as edgy as possible, especially anything he could slip under Cass's radar. 

Tadashi finished his oatmeal, folded up his study guide and stuffed it in his backpack. He poured some coffee into a to-go thermos and screwed the lid on. 

Just as he as about to leave, he just remembered something. "You okay with being on cafe duty tomorrow?"

"Yep. She told me." Hiro didn't even look up, preoccupied with peeling the last of the orange, then peeling off the separate sections. He popped half of the first one into his mouth. Looking up, he saw Tadashi looking at him wordlessly, as if he was about to say something.

"What?" Midway through the mouth full of orange.

"Sorry. It's nothing."

_He's beautiful._

Tadashi got his backpack on, coffee in hand.

Not in like, a 'that pop star is so hot' kind of way. Not in some 'oh, he cleans up nicely' kind of way. Not how you lust after celebrities, pro athletes, or the person two seats over in class. This went deeper, purer than any of that. This was Hiro, despite his bratty nature and smug attitude, something completing his word and giving his life real fulfillment. For all of Hiro's flaws, and the person he was, Tadashi loved him.

He could never really explain it without sounding weird. These special, protective feelings over Hiro went above and beyond a normal brotherly bond. It was like this ever since Tadashi was small and Hiro was an infant. Installing that GPS tracker was no accident. But- lately, things were changing. These feelings had evolved something just as strong, but slightly different. 

He was starting to _see_ something in Hiro that he didn't before. Maybe what he was seeing was the very symptoms of starting adulthood. Hiro was more independent, more free-thinking. His was that age where there is an impression of the adult you would ultimately become.

It might have been brought about by the physical changes Hiro was going through. The changes in his body, the changes in his demeanor. He caught himself looking at Hiro all the time. No, he told himself, it wasn't sexual. It wasn't romantic, either, to get that out of the way. The very thought was ridiculous. Come on. This was the Hiro he knew and loved, the person he'd swore to protect at all costs. But something about seeing Hiro grow up, before his own eyes- it made him think. Even at fourteen he was beginning to turn into a handsome young man in his own right. Tadashi was happy for him. He could see a future version of Hiro, what he would be like when he was grown up. 

He'd just get lost, imagining these sorts of things.

But it was a problem. He caught himself... _thinking_. _Seeing things._ Things he would rather be oblivious to.

It wasn't all the time. 

And at first, it wasn't so bad. Some things were objectively true facts. He just happened to notice that Hiro was growing up to be pretty good-looking compared to the other boys in his class. Nothing wrong with that. It was true. Tadashi was sure whomever Hiro dated would be really lucky- not that it didn't make him more than a little bit jealous. Because, he vividly remembered when _he_ was a freshman in high school, several years ago. Oh, man. How he suffered for his thick glasses, braces, his anime habit, and nerdy outfit. Sweater vest and everything. Tadashi grew up to be handsome, sure, but there was a long, perilous road getting there.

Lucky for Hiro, he had none of that. His interests were a little out of the ordinary, sure, but the only reason he ever had trouble fitting in with his peers was because he was the wrong age for them. If not for that, he would have a pretty easy time. No problem getting a date at the school dance. He was just _cute_ , Tadashi guessed.

Did Tadashi look like that, at that age?

Hiro's smile had changed, from something simple and innocent and childlike to a little bit smug, knowing, and sarcastic. And came with it that sharp attitude. It really should have gotten on Tadashi's nerves more. But every so often, there were those special moments where Hiro would smile at him- and really, it was _only_ Tadashi- and it was genuine. It was perfect. It was just something else. 

It stirred up some strange feelings in his stomach, that he couldn't really articulate.

If only it stopped there.

Sometimes when Hiro bent over, and took too long to pick things up, he couldn't help himself from staring. He was so skinny. Was Tadashi like that, at that age? He wore those same cargo shorts, at least four days a week. He had other clothes, funny he only ever wore those. His gaze kept roaming, as Hiro had his back turned. It was this involuntary thing. His eyes would follow that gentle curve of Hiro's bottom and slender hips. Oh, god. How was that even possible? This wasn't normal. This feeling was _physical_. 

Whenever he caught himself doing this, he'd look away. He couldn't believe himself sometimes.

But then he'd do it again. He thought it to himself, something he would never, ever, admit out loud: despite his scrawny frame. Like, he had... stuff in all the right places. No. No. What? Come on. He shut the thought out of his mind. Far, far away.

It kept coming back. Whenever Hiro sat a little bit closer than normal, as they were side-by-side on the couch, playing some video game. Hiro's leg would brush up against Tadashi's sometimes, since Mochi was occupying the whole extra cushion. It was nothing, really. Tadashi felt himself feeling a bit flustered, followed by a quick, imminent, automatic pang of unfettered self-hate. Normal stuff, really.

Or when Hiro stuck his tongue out just before he would suck on a straw. It looked funny to him, as if Hiro was trying to do it to get his attention. Of course, that was ridiculous.

Tadashi had his head screwed on right. This was his young, teenage brother he was thinking about. He couldn't be framing things in those terms. Just a passing thought, nothing more. It wasn't something he would seek out. He would never, ever in a million years admit it to anyone.

The latest addition to the GPS tracker, for keeping tabs on Hiro, at Aunt Cass's behest- was the monitor webcam in Hiro's room. Unfortunately, the plan mostly backfired horribly. All he managed to catch was Hiro putzing around, looking at Internet porn and masturbating a million times. Typical teenager, news at 11. And he sure as hell didn't want to look at that. Did he?

Because- there was that one occasion, late into the night when he was alone in the lab. 

It started when he checked his phone. In particular, he checked the camera feed. In particular, he saw what was happening in Hiro's room. Somehow, the camera had moved, so he had a perfect viewing angle of _what was happening_. Hiro was breathing heavy, appeared to be concentrating intently, ogling something at the computer, which was angled away and obscured from view. 

Tadashi chucked to himself, and muttered, 'little pervert'. That Hiro had an extensive porno collection was not news to him. He never went as far as to mention it to Aunt Cass, but it was an open secret. A very natural consequence of someone that age, with an open internet connection. It didn't cause any harm, so there was no sense in trying to stop him. Tadashi honestly wondered what kinds of weird shit Hiro was looking at. He was about to close it away. If he had any good sense, that's what he would've done.

He didn't. He kept watching. He saw Hiro's little hands, fighting with his fly, pulling his pants down lower on his slim hips, revealing some familiar boys' boxer-briefs that he'd seen so often on the floor. Didn't fit into a men's yet. 

And then Hiro slid a hand inside his briefs, and jerked it extremely quickly. In all of about ten seconds, maybe twenty if he was being generous, Hiro reached for a tissue and held it against his member, while he furrowed his brow, and trembled at the computer. It was not glamorous. The kid panted for air, flustered. He threw his head back, in bliss. Well, that was that. Tadashi felt himself flush in the face as well. He should _not_ be looking at this. No way in hell. 

And then Hiro didn't stop. Now, he could even see _it_ , in plainer view. Hiro's member, swollen and covered in cum. He started stroking it, again, and again, and again. Holy fuck, how much energy did he have? Multiple times in a row? When did it get to be that big? What started off as only his finger tips- now, he used his whole fist, closed over it. It was right there, in high definition. He saw Hiro's young member twitch and harden once more, and more pre-cum beaded out of the tip. It was crazy enough knowing that Hiro could actually perform sexually, but seeing _that_ \- he could hardly get used to the idea. And he had short pubes growing in, and everything. It shouldn't have been _hot_. He wouldn't admit to himself, that it was.

At this rate, he was really going to hurt himself. Hiro was not gentle about it now. He beat it off really quickly with a tight fist. No lube or anything. Tadashi felt himself actually feel a little bit concerned, it looked like he was going to chafe the skin or something. 

And then it stopped. Maybe, he actually had enough, and had gotten bored of that. Tadashi fidgeted with the collar of his shirt, which suddenly felt a little bit too hot and stuffy.

Hiro thrust a few fingers in his mouth, and sucked on them. This was a little bit weird, but okay. It reminded Tadashi of that straw from before. Oh, no. He popped his fingers out of his mouth, and- no. He shifted his legs a bit further apart, and upward, so he was resting them on the furniture- and inserted the fingers into himself. He started fucking himself on his fingers. Gently at first, then not so gently- much like he'd been treating his cock. 

Christ. 

He was better than this. He was a better person than to watch this. 

He shut the video feed off.

The whole fact of him watching this- it was _bad_. He could justify this to himself any which way. Sure, so he was only checking up on Hiro. Only trying to make sure he was out of trouble, and not harming himself or engaging in especially bad behavior online.

It was a very, very difficult trip home that day.

Yeah, so Tadashi had a midterm coming up. A game night with Fred and Go Go. A paper in his intro to information security systems class due, and nobody knew what the hell that class was about. He pushed these, and all the other thoughts out of his mind. There were other, more important things at the forefront. It was in his nature to ignore these kinds of problems, in hopes that they might go away. He bade Hiro, "See you later", and headed out the door.


End file.
